Does preexisting abnormality cause labor-delivery complications in fetuseswho will develop schizophrenia?

Many authors have suggested that theoretically the labor-delivery complicat ions (LDCs) that frequently appear in the histories of individuals with sch izophrenia represent the secondary consequence of preexistent abnormality i n the fetus, The question of whether LDCs are systematically associated wit h prenatal complications and fetal abnormality was studied in 70 singleton schizophrenia patients, in 23 monozygotic twin pairs discordant and 10 pair s concordant for schizophrenia, and in 33 individuals with inferred genetic risk for schizophrenia. Schizophrenia cases with signs of prenatal abnorma lity (reduced head size, increased minor physical anomalies, greater within -twin-pair birthweight differences) did not have more LDCs than other schiz ophrenia cases. LDCs were not more frequent in genetic-risk cases with cong enital malformations than in genetic-risk cases without malformations. Inst ead, individuals with schizophrenia who had a history of abnormal length of labor had significantly fewer pregnancy complications and minor physical a nomalies than did other individuals with schizophrenia, No support was foun d for suggestions that LDCs among individuals who have not yet developed sc hizophrenia are the result of identifiable preexistent fetal abnormality.